Human Energy Systems | Lesson 6 - Global Implications & Posttest

Download PDF of Lesson 6 Teacher's Guide

Overview

Students consider the impacts that rising carbon dioxide levels have on the Earth’s systems, discuss uncertainty in climate models and predictions, and consider the future of Earth’s systems given different CO₂ emissions scenarios.

Guiding Question

What does increasing CO₂ in the atmosphere mean for the future of the planet?

Activities in this Lesson

Activity 6.1: Using Models to Predict Future Conditions (50 min)
Activity 6.2: How Our Decisions Affect Earth’s Future (30 min)
Activity 6.3: Human Energy Systems Unit Posttest (20 min)

Unit Map

Human Energy Systems Lesson 6 Map

Target Student Performance

*Lesson 6 – Global Implications and Posttest (students as explainers and predictors)*
Activity	Target Performance
Activity 6.1 Using Models to Predict Future Conditions (50 min)	Students use the online Very, Very Simple Climate Model to make predictions about future atmospheric CO₂ concentrations and global temperatures based on CO₂ emissions scenarios.
Activity 6.2 How Our Decisions Affect Earth’s Future (30 min)	Students use graphs of projections from computer models to consider the impacts of increasing atmospheric CO₂ on Earth’s systems and on living things.
Activity 6.3: Human Energy Systems Unit Posttest (20 min)	Students show their initial proficiencies for the overall unit goals: 1. Questioning, investigating, and explaining how the Earth’s climate is changing 2. Explaining and predicting how carbon cycles and energy flows in Earth systems.

NGSS Performance Expectations

High School

Ecosystems: Interactions, Energy, and Dynamics. HS-LS2-5. Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere.
Earth and Human Activity. HS-ESS3-6. Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity.
Ecosystems: Interactions, Energy, and Dynamics. HS-LS2-7. Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
Earth’s Systems. HS-ESS2-2. Analyze geoscience data to make the claim that one change to Earth’s surface can create feedbacks that cause changes to other Earth systems.
Weather and Climate. HS-ESS2-4. Use a model to describe how variations in the flow of energy into and out of Earth’s systems result in changes in climate.
Earth and Human Activity. HS-ESS3-5. Analyze geoscience data and the results from global climate models to make an evidence-based forecast of the current rate of global or regional climate change and associated future impacts to Earth systems.

Middle School

Human Impacts. MS-ESS3-4. Construct an argument supported by evidence for how increases in human population and per-capital consumption of natural resources impact Earth's systems.
Earth and Human Activity. MS-ESS3-3. Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.
Earth and Human Activity. MS-ESS3-5. Ask questions to clarify evidence of the factors that have caused the rise in global temperatures over the past century.

Three-dimensional Learning Progression

In Lesson 4 students studied global CO₂ fluxes changed atmospheric CO₂ concentrations, including the key role of the human-caused flux from burning fossil fuels. In Lesson 5 the studied human technological systems and activities and how they contribute to the unbalanced fossil fuel flux. In Lesson 6, they return to the global scale, considering how this unbalanced flux affects other aspects of Earth systems, such global temperatures, sea level, and Arctic sea ice. They use computer models to map out different scenarios for the future, studying how the future of the planet will depend on humans’ activities and decisions. Our goal is to help students see how those models are grounded in the scientific models and principles that they have studied, and to appreciate both the power and the limits of those models.

Key Ideas and Practices for Each Activity

Activity 6.1 helps students examine how to use data from large-scale data sets to make predictions about what will happen in the future. This activity aims to help students distinguish between data sets that have predictable short-term variation (like the Keeling Curve) and data sets that have unpredictable (random or stochastic) short-term variation (like Arctic sea ice, global temperature, and sea level rise). We can use the stable seasonal cycle in the Keeling Curve to make predictions about CO₂levels in the future months, years, and long term. This is because the short-term variation is due to a predictable flux of carbon atoms between the atmosphere and the biomass as a result of photosynthesis and cellular respiration. The long-term trend, which is a result of fossil fuel consumption, can be used to make predictions further into the future. Other phenomena such as Arctic Sea ice extent, global temperatures, and sea level have much more random variation that affect their short-term patterns and make them less useful for making precise predictions about the next few years. However, we can use the long-term trends in these data to make predictions about overall patterns in the future.

Activity 6.2 uses a very simple climate model to make predictions about future atmospheric CO₂concentrations and global temperatures. Using this model students learn that even if CO₂ emissions remain constant or begin to decrease, atmospheric CO₂ (and therefore global temperatures) will continue to rise over the next century.

Activity 6.3 helps students begin to think about how our decisions affect Earth’s future. This activity builds on the simple climate model in Activity 2 to show how scientists use models to predict what Earth’s systems might look like in the future based on various emissions scenarios. These models operate with a degree of uncertainty but are useful for examining how different emissions scenarios or mitigation strategies may affect Earth’s systems. We want the students to understand that computer models are useful even if they cannot predict the future with 100% accuracy, and that long-term trends from the past are valuable pieces of evidence on which to base future projections. This lesson concludes with questions about how our actions affect Earth’s future that you may wish to investigate further.

Activity 6.4 of the unit is a posttest, enabling you to monitor your students’ progress in understanding patterns in Earth systems, including climate change and global carbon cycling.

Key Carbon-Transforming Processes: Combustion, Photosynthesis, Fossil Fuel Formation, Cellular Respiration

Content Boundaries and Extensions